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73042f01 | 1 | /************************************************************************** |
2 | * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. * | |
3 | * * | |
4 | * Author: The ALICE Off-line Project. * | |
5 | * Contributors are mentioned in the code where appropriate. * | |
6 | * * | |
7 | * Permission to use, copy, modify and distribute this software and its * | |
8 | * documentation strictly for non-commercial purposes is hereby granted * | |
9 | * without fee, provided that the above copyright notice appears in all * | |
10 | * copies and that both the copyright notice and this permission notice * | |
11 | * appear in the supporting documentation. The authors make no claims * | |
12 | * about the suitability of this software for any purpose. It is * | |
13 | * provided "as is" without express or implied warranty. * | |
14 | **************************************************************************/ | |
15 | ||
16 | /* | |
17 | $Log$ | |
18 | Revision 1.1.2.1 2000/06/25 08:53:55 kowal2 | |
19 | Splitted from AliTPCtracking | |
20 | ||
21 | */ | |
22 | ||
23 | //------------------------------------------------------- | |
24 | // Implementation of the TPC tracker | |
25 | // | |
26 | // Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch | |
27 | //------------------------------------------------------- | |
28 | ||
29 | #include "AliTPCtracker.h" | |
30 | #include "AliTPCcluster.h" | |
31 | #include <TObjArray.h> | |
32 | #include <TFile.h> | |
33 | #include "AliTPCClustersArray.h" | |
34 | #include "AliTPCClustersRow.h" | |
35 | ||
36 | const AliTPCParam *AliTPCtracker::AliTPCSector::fgParam; | |
37 | ||
38 | //_____________________________________________________________________________ | |
39 | Double_t SigmaY2(Double_t r, Double_t tgl, Double_t pt) | |
40 | { | |
41 | // | |
42 | // Parametrised error of the cluster reconstruction (pad direction) | |
43 | // | |
44 | // Sigma rphi | |
45 | const Float_t kArphi=0.41818e-2; | |
46 | const Float_t kBrphi=0.17460e-4; | |
47 | const Float_t kCrphi=0.30993e-2; | |
48 | const Float_t kDrphi=0.41061e-3; | |
49 | ||
50 | pt=TMath::Abs(pt)*1000.; | |
51 | Double_t x=r/pt; | |
52 | tgl=TMath::Abs(tgl); | |
53 | Double_t s=kArphi - kBrphi*r*tgl + kCrphi*x*x + kDrphi*x; | |
54 | if (s<0.4e-3) s=0.4e-3; | |
55 | s*=1.3; //Iouri Belikov | |
56 | ||
57 | return s; | |
58 | } | |
59 | ||
60 | //_____________________________________________________________________________ | |
61 | Double_t SigmaZ2(Double_t r, Double_t tgl) | |
62 | { | |
63 | // | |
64 | // Parametrised error of the cluster reconstruction (drift direction) | |
65 | // | |
66 | // Sigma z | |
67 | const Float_t kAz=0.39614e-2; | |
68 | const Float_t kBz=0.22443e-4; | |
69 | const Float_t kCz=0.51504e-1; | |
70 | ||
71 | ||
72 | tgl=TMath::Abs(tgl); | |
73 | Double_t s=kAz - kBz*r*tgl + kCz*tgl*tgl; | |
74 | if (s<0.4e-3) s=0.4e-3; | |
75 | s*=1.3; //Iouri Belikov | |
76 | ||
77 | return s; | |
78 | } | |
79 | ||
80 | //_____________________________________________________________________________ | |
81 | inline Double_t f1(Double_t x1,Double_t y1, | |
82 | Double_t x2,Double_t y2, | |
83 | Double_t x3,Double_t y3) | |
84 | { | |
85 | //----------------------------------------------------------------- | |
86 | // Initial approximation of the track curvature | |
87 | //----------------------------------------------------------------- | |
88 | Double_t d=(x2-x1)*(y3-y2)-(x3-x2)*(y2-y1); | |
89 | Double_t a=0.5*((y3-y2)*(y2*y2-y1*y1+x2*x2-x1*x1)- | |
90 | (y2-y1)*(y3*y3-y2*y2+x3*x3-x2*x2)); | |
91 | Double_t b=0.5*((x2-x1)*(y3*y3-y2*y2+x3*x3-x2*x2)- | |
92 | (x3-x2)*(y2*y2-y1*y1+x2*x2-x1*x1)); | |
93 | ||
94 | Double_t xr=TMath::Abs(d/(d*x1-a)), yr=d/(d*y1-b); | |
95 | ||
96 | return -xr*yr/sqrt(xr*xr+yr*yr); | |
97 | } | |
98 | ||
99 | ||
100 | //_____________________________________________________________________________ | |
101 | inline Double_t f2(Double_t x1,Double_t y1, | |
102 | Double_t x2,Double_t y2, | |
103 | Double_t x3,Double_t y3) | |
104 | { | |
105 | //----------------------------------------------------------------- | |
106 | // Initial approximation of the track curvature times center of curvature | |
107 | //----------------------------------------------------------------- | |
108 | Double_t d=(x2-x1)*(y3-y2)-(x3-x2)*(y2-y1); | |
109 | Double_t a=0.5*((y3-y2)*(y2*y2-y1*y1+x2*x2-x1*x1)- | |
110 | (y2-y1)*(y3*y3-y2*y2+x3*x3-x2*x2)); | |
111 | Double_t b=0.5*((x2-x1)*(y3*y3-y2*y2+x3*x3-x2*x2)- | |
112 | (x3-x2)*(y2*y2-y1*y1+x2*x2-x1*x1)); | |
113 | ||
114 | Double_t xr=TMath::Abs(d/(d*x1-a)), yr=d/(d*y1-b); | |
115 | ||
116 | return -a/(d*y1-b)*xr/sqrt(xr*xr+yr*yr); | |
117 | } | |
118 | ||
119 | //_____________________________________________________________________________ | |
120 | inline Double_t f3(Double_t x1,Double_t y1, | |
121 | Double_t x2,Double_t y2, | |
122 | Double_t z1,Double_t z2) | |
123 | { | |
124 | //----------------------------------------------------------------- | |
125 | // Initial approximation of the tangent of the track dip angle | |
126 | //----------------------------------------------------------------- | |
127 | return (z1 - z2)/sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2)); | |
128 | } | |
129 | ||
130 | //_____________________________________________________________________________ | |
131 | Int_t AliTPCtracker::FindProlongation(AliTPCseed& t, const AliTPCSector *sec, | |
132 | Int_t s, Int_t rf) | |
133 | { | |
134 | //----------------------------------------------------------------- | |
135 | // This function tries to find a track prolongation. | |
136 | //----------------------------------------------------------------- | |
137 | const Int_t kSKIP=(t.GetNumberOfClusters()<10) ? | |
138 | 10 : Int_t(0.5*sec->GetNRows()); | |
139 | Int_t tryAgain=kSKIP; | |
140 | Double_t alpha=sec->GetAlpha(); | |
141 | Int_t ns=Int_t(2*TMath::Pi()/alpha+0.5); | |
142 | ||
143 | for (Int_t nr=sec->GetRowNumber(t.GetX())-1; nr>=rf; nr--) { | |
144 | Double_t x=sec->GetX(nr), ymax=sec->GetMaxY(nr); | |
145 | if (!t.PropagateTo(x)) return 0; | |
146 | ||
147 | AliTPCcluster *cl=0; | |
148 | UInt_t index=0; | |
149 | Double_t maxchi2=12.; | |
150 | const AliTPCRow &krow=sec[s][nr]; | |
151 | Double_t sy2=SigmaY2(t.GetX(),t.GetTgl(),t.GetPt()); | |
152 | Double_t sz2=SigmaZ2(t.GetX(),t.GetTgl()); | |
153 | Double_t road=4.*sqrt(t.GetSigmaY2() + sy2), y=t.GetY(), z=t.GetZ(); | |
154 | ||
155 | if (road>30) { | |
156 | if (t.GetNumberOfClusters()>4) | |
157 | cerr<<t.GetNumberOfClusters() | |
158 | <<"FindProlongation warning: Too broad road !\n"; | |
159 | return 0; | |
160 | } | |
161 | ||
162 | if (krow) { | |
163 | for (Int_t i=krow.Find(y-road); i<krow; i++) { | |
164 | AliTPCcluster* c=(AliTPCcluster*)(krow[i]); | |
165 | if (c->GetY() > y+road) break; | |
166 | if (c->IsUsed()) continue; | |
167 | if ((c->GetZ()-z)*(c->GetZ()-z) > 16.*(t.GetSigmaZ2()+sz2)) continue; | |
168 | Double_t chi2=t.GetPredictedChi2(c); | |
169 | if (chi2 > maxchi2) continue; | |
170 | maxchi2=chi2; | |
171 | cl=c; | |
172 | index=krow.GetIndex(i); | |
173 | } | |
174 | } | |
175 | if (cl) { | |
176 | Float_t l=sec->GetPadPitchWidth(); | |
177 | t.SetSampledEdx(cl->GetQ()/l,t.GetNumberOfClusters()); | |
178 | t.Update(cl,maxchi2,index); | |
179 | tryAgain=kSKIP; | |
180 | } else { | |
181 | if (tryAgain==0) break; | |
182 | if (y > ymax) { | |
183 | s = (s+1) % ns; | |
184 | if (!t.Rotate(alpha)) return 0; | |
185 | } else if (y <-ymax) { | |
186 | s = (s-1+ns) % ns; | |
187 | if (!t.Rotate(-alpha)) return 0; | |
188 | } | |
189 | tryAgain--; | |
190 | } | |
191 | } | |
192 | ||
193 | return 1; | |
194 | ||
195 | } | |
196 | ||
197 | //_____________________________________________________________________________ | |
198 | void | |
199 | AliTPCtracker::MakeSeeds(TObjArray& seeds,const AliTPCSector *sec, Int_t max, | |
200 | Int_t i1, Int_t i2) | |
201 | { | |
202 | //----------------------------------------------------------------- | |
203 | // This function creates track seeds. | |
204 | //----------------------------------------------------------------- | |
205 | Double_t x[5], c[15]; | |
206 | ||
207 | Double_t alpha=sec->GetAlpha(), shift=sec->GetAlphaShift(); | |
208 | Double_t cs=cos(alpha), sn=sin(alpha); | |
209 | ||
210 | Double_t x1 =sec->GetX(i1); | |
211 | Double_t xx2=sec->GetX(i2); | |
212 | ||
213 | for (Int_t ns=0; ns<max; ns++) { | |
214 | Int_t nl=sec[(ns-1+max)%max][i2]; | |
215 | Int_t nm=sec[ns][i2]; | |
216 | Int_t nu=sec[(ns+1)%max][i2]; | |
217 | const AliTPCRow& kr1=sec[ns][i1]; | |
218 | for (Int_t is=0; is < kr1; is++) { | |
219 | Double_t y1=kr1[is]->GetY(), z1=kr1[is]->GetZ(); | |
220 | for (Int_t js=0; js < nl+nm+nu; js++) { | |
221 | const AliTPCcluster *kcl; | |
222 | Double_t x2, y2, z2; | |
223 | Double_t x3=0.,y3=0.; | |
224 | ||
225 | if (js<nl) { | |
226 | const AliTPCRow& kr2=sec[(ns-1+max)%max][i2]; | |
227 | kcl=kr2[js]; | |
228 | y2=kcl->GetY(); z2=kcl->GetZ(); | |
229 | x2= xx2*cs+y2*sn; | |
230 | y2=-xx2*sn+y2*cs; | |
231 | } else | |
232 | if (js<nl+nm) { | |
233 | const AliTPCRow& kr2=sec[ns][i2]; | |
234 | kcl=kr2[js-nl]; | |
235 | x2=xx2; y2=kcl->GetY(); z2=kcl->GetZ(); | |
236 | } else { | |
237 | const AliTPCRow& kr2=sec[(ns+1)%max][i2]; | |
238 | kcl=kr2[js-nl-nm]; | |
239 | y2=kcl->GetY(); z2=kcl->GetZ(); | |
240 | x2=xx2*cs-y2*sn; | |
241 | y2=xx2*sn+y2*cs; | |
242 | } | |
243 | ||
244 | Double_t zz=z1 - z1/x1*(x1-x2); | |
245 | if (TMath::Abs(zz-z2)>5.) continue; | |
246 | ||
247 | Double_t d=(x2-x1)*(0.-y2)-(0.-x2)*(y2-y1); | |
248 | if (d==0.) {cerr<<"MakeSeeds warning: Straight seed !\n"; continue;} | |
249 | ||
250 | x[0]=y1; | |
251 | x[1]=z1; | |
252 | x[2]=f1(x1,y1,x2,y2,x3,y3); | |
253 | if (TMath::Abs(x[2]) >= 0.0066) continue; | |
254 | x[3]=f2(x1,y1,x2,y2,x3,y3); | |
255 | //if (TMath::Abs(x[2]*x1-x[3]) >= 0.99999) continue; | |
256 | x[4]=f3(x1,y1,x2,y2,z1,z2); | |
257 | if (TMath::Abs(x[4]) > 1.2) continue; | |
258 | Double_t a=asin(x[3]); | |
259 | Double_t zv=z1 - x[4]/x[2]*(a+asin(x[2]*x1-x[3])); | |
260 | if (TMath::Abs(zv)>10.) continue; | |
261 | ||
262 | Double_t sy1=kr1[is]->GetSigmaY2(), sz1=kr1[is]->GetSigmaZ2(); | |
263 | Double_t sy2=kcl->GetSigmaY2(), sz2=kcl->GetSigmaZ2(); | |
264 | Double_t sy3=100*0.025, sy=0.1, sz=0.1; | |
265 | ||
266 | Double_t f20=(f1(x1,y1+sy,x2,y2,x3,y3)-x[2])/sy; | |
267 | Double_t f22=(f1(x1,y1,x2,y2+sy,x3,y3)-x[2])/sy; | |
268 | Double_t f24=(f1(x1,y1,x2,y2,x3,y3+sy)-x[2])/sy; | |
269 | Double_t f30=(f2(x1,y1+sy,x2,y2,x3,y3)-x[3])/sy; | |
270 | Double_t f32=(f2(x1,y1,x2,y2+sy,x3,y3)-x[3])/sy; | |
271 | Double_t f34=(f2(x1,y1,x2,y2,x3,y3+sy)-x[3])/sy; | |
272 | Double_t f40=(f3(x1,y1+sy,x2,y2,z1,z2)-x[4])/sy; | |
273 | Double_t f41=(f3(x1,y1,x2,y2,z1+sz,z2)-x[4])/sz; | |
274 | Double_t f42=(f3(x1,y1,x2,y2+sy,z1,z2)-x[4])/sy; | |
275 | Double_t f43=(f3(x1,y1,x2,y2,z1,z2+sz)-x[4])/sz; | |
276 | ||
277 | c[0]=sy1; | |
278 | c[1]=0.; c[2]=sz1; | |
279 | c[3]=f20*sy1; c[4]=0.; c[5]=f20*sy1*f20+f22*sy2*f22+f24*sy3*f24; | |
280 | c[6]=f30*sy1; c[7]=0.; c[8]=f30*sy1*f20+f32*sy2*f22+f34*sy3*f24; | |
281 | c[9]=f30*sy1*f30+f32*sy2*f32+f34*sy3*f34; | |
282 | c[10]=f40*sy1; c[11]=f41*sz1; c[12]=f40*sy1*f20+f42*sy2*f22; | |
283 | c[13]=f40*sy1*f30+f42*sy2*f32; | |
284 | c[14]=f40*sy1*f40+f41*sz1*f41+f42*sy2*f42+f43*sz2*f43; | |
285 | ||
286 | UInt_t index=kr1.GetIndex(is); | |
287 | AliTPCseed *track=new AliTPCseed(index, x, c, x1, ns*alpha+shift); | |
288 | Float_t l=sec->GetPadPitchWidth(); | |
289 | track->SetSampledEdx(kr1[is]->GetQ()/l,0); | |
290 | ||
291 | Int_t rc=FindProlongation(*track,sec,ns,i2); | |
292 | if (rc<0 || track->GetNumberOfClusters()<(i1-i2)/2) delete track; | |
293 | else seeds.AddLast(track); | |
294 | } | |
295 | } | |
296 | } | |
297 | } | |
298 | ||
299 | //_____________________________________________________________________________ | |
300 | void AliTPCtracker::Clusters2Tracks(const AliTPCParam *par, TFile *of) { | |
301 | //----------------------------------------------------------------- | |
302 | // This is a track finder. | |
303 | //----------------------------------------------------------------- | |
304 | TDirectory *savedir=gDirectory; | |
305 | ||
306 | if (!of->IsOpen()) { | |
307 | cerr<<"AliTPC::Clusters2Tracks(): output file not open !\n"; | |
308 | return; | |
309 | } | |
310 | ||
311 | AliTPCClustersArray carray; | |
312 | carray.Setup(par); | |
313 | carray.SetClusterType("AliTPCcluster"); | |
314 | carray.ConnectTree("Segment Tree"); | |
315 | ||
316 | of->cd(); | |
317 | TTree tracktree("TreeT","Tree with TPC tracks"); | |
318 | AliTPCtrack *iotrack=0; | |
319 | tracktree.Branch("tracks","AliTPCtrack",&iotrack,32000,0); | |
320 | ||
321 | AliTPCSector::SetParam(par); | |
322 | ||
323 | const Int_t kNIS=par->GetNInnerSector()/2; | |
324 | AliTPCSSector *ssec=new AliTPCSSector[kNIS]; | |
325 | Int_t nlow=ssec->GetNRows(); | |
326 | ||
327 | const Int_t kNOS=par->GetNOuterSector()/2; | |
328 | AliTPCLSector *lsec=new AliTPCLSector[kNOS]; | |
329 | Int_t nup=lsec->GetNRows(); | |
330 | ||
331 | //Load outer sectors | |
332 | UInt_t index; | |
333 | Int_t i,j; | |
334 | ||
335 | j=Int_t(carray.GetTree()->GetEntries()); | |
336 | for (i=0; i<j; i++) { | |
337 | AliSegmentID *s=carray.LoadEntry(i); | |
338 | Int_t sec,row; | |
339 | par->AdjustSectorRow(s->GetID(),sec,row); | |
340 | if (sec<kNIS*2) continue; | |
341 | AliTPCClustersRow *clrow=carray.GetRow(sec,row); | |
342 | Int_t ncl=clrow->GetArray()->GetEntriesFast(); | |
343 | while (ncl--) { | |
344 | AliTPCcluster *c=(AliTPCcluster*)(*clrow)[ncl]; | |
345 | index=(((sec<<8)+row)<<16)+ncl; | |
346 | lsec[(sec-kNIS*2)%kNOS][row].InsertCluster(c,index); | |
347 | } | |
348 | } | |
349 | ||
350 | //find track seeds | |
351 | TObjArray seeds(20000); | |
352 | Int_t nrows=nlow+nup; | |
353 | Int_t gap=Int_t(0.125*nrows), shift=Int_t(0.5*gap); | |
354 | MakeSeeds(seeds, lsec, kNOS, nup-1, nup-1-gap); | |
355 | MakeSeeds(seeds, lsec, kNOS, nup-1-shift, nup-1-shift-gap); | |
356 | seeds.Sort(); | |
357 | ||
358 | //tracking in outer sectors | |
359 | Int_t nseed=seeds.GetEntriesFast(); | |
360 | for (i=0; i<nseed; i++) { | |
361 | AliTPCseed *pt=(AliTPCseed*)seeds.UncheckedAt(i), &t=*pt; | |
362 | Double_t alpha=t.GetAlpha(); | |
363 | if (alpha > 2.*TMath::Pi()) alpha -= 2.*TMath::Pi(); | |
364 | if (alpha < 0. ) alpha += 2.*TMath::Pi(); | |
365 | Int_t ns=Int_t(alpha/lsec->GetAlpha())%kNOS; | |
366 | ||
367 | if (FindProlongation(t,lsec,ns)) { | |
368 | t.UseClusters(&carray); | |
369 | continue; | |
370 | } | |
371 | delete seeds.RemoveAt(i); | |
372 | } | |
373 | ||
374 | //unload outer sectors | |
375 | for (i=0; i<kNOS; i++) { | |
376 | for (j=0; j<nup; j++) { | |
377 | if (carray.GetRow(i+kNIS*2,j)) carray.ClearRow(i+kNIS*2,j); | |
378 | if (carray.GetRow(i+kNIS*2+kNOS,j)) carray.ClearRow(i+kNIS*2+kNOS,j); | |
379 | } | |
380 | } | |
381 | ||
382 | //load inner sectors | |
383 | j=Int_t(carray.GetTree()->GetEntries()); | |
384 | for (i=0; i<j; i++) { | |
385 | AliSegmentID *s=carray.LoadEntry(i); | |
386 | Int_t sec,row; | |
387 | par->AdjustSectorRow(s->GetID(),sec,row); | |
388 | if (sec>=kNIS*2) continue; | |
389 | AliTPCClustersRow *clrow=carray.GetRow(sec,row); | |
390 | Int_t ncl=clrow->GetArray()->GetEntriesFast(); | |
391 | while (ncl--) { | |
392 | AliTPCcluster *c=(AliTPCcluster*)(*clrow)[ncl]; | |
393 | index=(((sec<<8)+row)<<16)+ncl; | |
394 | ssec[sec%kNIS][row].InsertCluster(c,index); | |
395 | } | |
396 | } | |
397 | ||
398 | //tracking in inner sectors | |
399 | Int_t found=0; | |
400 | for (i=0; i<nseed; i++) { | |
401 | AliTPCseed *pt=(AliTPCseed*)seeds.UncheckedAt(i), &t=*pt; | |
402 | if (!pt) continue; | |
403 | Int_t nc=t.GetNumberOfClusters(); | |
404 | ||
405 | Double_t alpha=t.GetAlpha() - ssec->GetAlphaShift(); | |
406 | if (alpha > 2.*TMath::Pi()) alpha -= 2.*TMath::Pi(); | |
407 | if (alpha < 0. ) alpha += 2.*TMath::Pi(); | |
408 | Int_t ns=Int_t(alpha/ssec->GetAlpha())%kNIS; | |
409 | ||
410 | alpha=ns*ssec->GetAlpha() + ssec->GetAlphaShift() - t.GetAlpha(); | |
411 | ||
412 | if (t.Rotate(alpha)) { | |
413 | if (FindProlongation(t,ssec,ns)) { | |
414 | if (t.GetNumberOfClusters() >= Int_t(0.4*nrows)) { | |
415 | t.CookdEdx(); | |
416 | //t.CookLabel(&carray); | |
417 | iotrack=pt; | |
418 | tracktree.Fill(); | |
419 | t.UseClusters(&carray,nc); | |
420 | cerr<<found++<<'\r'; | |
421 | } | |
422 | } | |
423 | } | |
424 | delete seeds.RemoveAt(i); | |
425 | } | |
426 | tracktree.Write(); | |
427 | ||
428 | //unload inner sectors | |
429 | for (i=0; i<kNIS; i++) { | |
430 | for (j=0; j<nlow; j++) { | |
431 | if (carray.GetRow(i,j)) carray.ClearRow(i,j); | |
432 | if (carray.GetRow(i+kNIS,j)) carray.ClearRow(i+kNIS,j); | |
433 | } | |
434 | } | |
435 | ||
436 | cerr<<"Number of found tracks : "<<found<<endl; | |
437 | ||
438 | delete[] ssec; | |
439 | delete[] lsec; | |
440 | ||
441 | savedir->cd(); | |
442 | } | |
443 | ||
444 | //_________________________________________________________________________ | |
445 | void | |
446 | AliTPCtracker::AliTPCRow::InsertCluster(const AliTPCcluster* c, UInt_t index) { | |
447 | //----------------------------------------------------------------------- | |
448 | // Insert a cluster into this pad row in accordence with its y-coordinate | |
449 | //----------------------------------------------------------------------- | |
450 | if (fN==kMAXCLUSTER) { | |
451 | cerr<<"AliTPCRow::InsertCluster(): Too many clusters !\n"; return; | |
452 | } | |
453 | if (fN==0) {fIndex[0]=index; fClusters[fN++]=c; return;} | |
454 | Int_t i=Find(c->GetY()); | |
455 | memmove(fClusters+i+1 ,fClusters+i,(fN-i)*sizeof(AliTPCcluster*)); | |
456 | memmove(fIndex +i+1 ,fIndex +i,(fN-i)*sizeof(UInt_t)); | |
457 | fIndex[i]=index; fClusters[i]=c; fN++; | |
458 | } | |
459 | ||
460 | //___________________________________________________________________ | |
461 | Int_t AliTPCtracker::AliTPCRow::Find(Double_t y) const { | |
462 | //----------------------------------------------------------------------- | |
463 | // Return the index of the nearest cluster | |
464 | //----------------------------------------------------------------------- | |
465 | if (y <= fClusters[0]->GetY()) return 0; | |
466 | if (y > fClusters[fN-1]->GetY()) return fN; | |
467 | Int_t b=0, e=fN-1, m=(b+e)/2; | |
468 | for (; b<e; m=(b+e)/2) { | |
469 | if (y > fClusters[m]->GetY()) b=m+1; | |
470 | else e=m; | |
471 | } | |
472 | return m; | |
473 | } | |
474 | ||
475 | //_____________________________________________________________________________ | |
476 | void AliTPCtracker::AliTPCseed::CookdEdx(Double_t low, Double_t up) { | |
477 | //----------------------------------------------------------------- | |
478 | // This funtion calculates dE/dX within the "low" and "up" cuts. | |
479 | //----------------------------------------------------------------- | |
480 | Int_t i; | |
481 | ||
482 | Int_t swap;//stupid sorting | |
483 | do { | |
484 | swap=0; | |
485 | for (i=0; i<fN-1; i++) { | |
486 | if (fdEdx[i]<=fdEdx[i+1]) continue; | |
487 | Float_t tmp=fdEdx[i]; fdEdx[i]=fdEdx[i+1]; fdEdx[i+1]=tmp; | |
488 | swap++; | |
489 | } | |
490 | } while (swap); | |
491 | ||
492 | Int_t nl=Int_t(low*fN), nu=Int_t(up*fN); | |
493 | Float_t dedx=0; | |
494 | for (i=nl; i<=nu; i++) dedx += fdEdx[i]; | |
495 | dedx /= (nu-nl+1); | |
496 | SetdEdx(dedx); | |
497 | } | |
498 | ||
499 | //_____________________________________________________________________________ | |
500 | void AliTPCtracker::AliTPCseed::UseClusters(AliTPCClustersArray *ca, Int_t n) { | |
501 | //----------------------------------------------------------------- | |
502 | // This function marks clusters associated with this track. | |
503 | //----------------------------------------------------------------- | |
504 | Int_t sec,row,ncl; | |
505 | for (Int_t i=n; i<fN; i++) { | |
506 | GetCluster(i,sec,row,ncl); | |
507 | AliTPCClustersRow *clrow=ca->GetRow(sec,row); | |
508 | AliTPCcluster *c=(AliTPCcluster*)(*clrow)[ncl]; | |
509 | c->Use(); | |
510 | } | |
511 | } | |
512 | ||
513 |